Forget phone sex. The latest trend sweeping Hollywood seems to be booty calls in the bathroom. Diane Lane and Olivier Martinez get it on in a cafe stall in Unfaithful; randy terrorist Mia Kirshner and passenger Rudolf Martin have a rest-room romp aboard a plane on 24; and real-life couple Enrique Iglesias and Anna Kournikova aren’t exactly powdering their noses in his ”Escape” video. What’s the key to getting jiggy in the john? ”You have to be really quiet,” says Joshua Piven, coauthor of The Worst-Case Scenario Survival Handbook: Dating and Sex. ”Then, it’s a pretty small space, so you have to be creative with positioning.” Sexperts claim the lure is simple. ”The risk of getting caught always makes sex more exciting,” says Love Around the House author Dr. Ava Cadell. ”And it’s very convenient… because you can wash up easily.”